How can I set a property type to nullable?

[Bevis-Z]

Hi guys,

Just wondering is there any methods to set a property to return nullable value if there is no such info have been provided in the context?

It seems like OpenAI provides a Unit type for setting up the type of the json_schema like the following code:
{ "name": "get_weather", "description": "Fetches the weather in the given location", "strict": true, "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "The location to get the weather for" }, "unit": { "type": ["string", "null"], "description": "The unit to return the temperature in", "enum": ["F", "C"] } }, "additionalProperties": false, "required": [ "location", "unit" ] } }

It allows us to specify the type as unit with a type of "string", "null".
"type": ["string", "null"],

Does Betalgo has something similar? I can't find it by myself, as the property type in Betalgo seems could only be set as a string.

Thanks